Fluorescent lighting circuit

ABSTRACT

The specification discloses a circuit for starting a plurality of fluorescent lamps. The ordinary fluorescent lamp requires a heavy inductance, usually referred to as a ballast, for starting the lamps. The ballast is heavy and expensive. A lightweight resistance could be substituted for the ballast, if a simple means could be found to start the lamp. The present invention uses a single transformer to supply a higher voltage of, for example, 180 volts, for starting and a switching arrangement for switching the transformer from lamp to lamp. After the lamps are started they are switched onto a standard line voltage of 120 volts, for example. Thus, a single transformer is required to light a number of lamps.

United States Patent Gorton 1 Mayz, 1972 [54] FLUORESCENT LIGHTINGCIRCUIT [22] Filed: Sept. 24, 1969 [21] Appl.No.: 860,554

[52} [1.8. CI ..3l5/l87, 315/100, 315/228, 315/276, 315/323 [51] Int.Cl. ..H05b 37/00 [58] Field ofSearch "315/100, 100 U, 160, 172, 173,315/186, 187, 228, 250, 276, 314, 323

[56] References Cited UNITED STATES PATENTS 3,243,650 5/1966 Hawkins eta1. ..315/l6l FOREIGN PATENTS OR APPLICATIONS 838,034 5/1952 Germany315/100 X 1,150,758 6/1963 Germany ..3l5/l73 X Primary Examiner-Roy LakeAssistant Examiner-Lawrence .l. Dahl Attorney-Charles L. Lovercheck [57]ABSTRACT The specification discloses a circuit for starting a pluralityof fluorescent lamps. The ordinary fluorescent lamp requires a heavyinductance, usually referred to as a ballast, for starting the lamps.The ballast is heavy and expensive. A lightweight resistance could besubstituted for the ballast, if a simple means could be found to startthe lamp. The present invention uses a single transformer to supply ahigher voltage of, for example, 180 volts, for starting and a switchingarrangement for switching the transformer from lamp to lamp. After thelamps are started they are switched onto a standard line voltage of 120volts, for example. Thus, a single transformer is required to light anumber of lamps.

1 Claims, 3 Drawing Figures Patented May 2, 1972 3,666316 2 Sheets-Sheet1 Patented May 2, 1972 3,660,716

2 Sheets-Shut 2 Fip E Gazrou 0&4 A AMM FLUORESCENT LIGHTING cmcur'rDESCRIPTION OF PRIOR ART The iron core ballast, as it is known today, isused to start the fluorescent tube/tubes and then switched out of thecircuit and the tube-tubes function on line voltage along.

OBJECTS OF THE INVENTION An object of this invention is to provide animprovement in fluorescent circuits and, more particularly, an improvedlighting circuit for fluorescent lamps.

Another object of the invention is to provide a simple, inexpensiveresistor circuit for 48 inch tubes or longer.

Another object of the invention is to provide a single starting circuitfor fluorescent lamps.

Yet another object of the invention is to provide a functioningfluorescent circuit which is light in weight, low in manufacturing cost,and inexpensive to maintain.

DESCRIPTION OF THE DRAWINGS FIG. 1 shows a switch-out ballast circuit;

FIG. 2 shows a tube and a plug-in removable unit according to theinvention; and

FIG. 3 is a solid state type starter circuit.

DETAILED DESCRIPTION OF THE DRAWINGS In the drawings, referring to theembodiment shown in FIG. 1, three fluorescent tubes 10, 1 1, and 12 areshown, each having a starter 13, 14, and 15, respectively, and eachhaving a ballaster resistor 16, 17, and 18, respectively, connected inseries therewith.

The source of power made up of lines 130 and 131 may be connected, forexample, to a 120 volt A. C. line and the A. C. line may be connected tothe fluorescent lights through a switch 25 having contacts SW1, SW2, andSW3, respectively.

The line switch 25 connects the power supply from lines 130 and 131 tothe transformer 22. The auto transformer 22 will put out approximately180 volts for starting the tubes. The autotransformer output isconnected to the tubes selectively through capacitor 20 and 21 by theswitch 24 by the selected contacts 3, 4, 3, 4', 3", and 4",respectively. When the switch contacts are switched from contacts 3, 4to contacts 3,4, for example, the starting voltage will be removed fromcontacts 3, 4 and applied to contacts 3 and 4. Thus, the fluorescenttubes will be started by the higher voltage and will operate on the linevoltage.

Referring to the embodiment of the invention shown in F IG. 2, thefluorescent tube has a starter 113 supported in the unit 140. The unitstarter is plugged into the other wires 1, 2, 3, and 4 by a suitablejack arrangement and is likewise connected to the power lines 130 and131 by the suitable jack arrangement shown.

A fuse H23 protects the line from malfunction of the circuit. An autotransformer 122 has its output connected through condensers and 121 intoparallel connection with the lines and 131. Thus, the output of the autotransformer 122 and the starter 113 can be switched intermittently andselectively to a plurality of tubes 110 so that all of the tubes can bestarted from the same power source.

Now with reference to FIG. 3 which shows a portable battery operatedcircuit for switching the ballast out of the circuit, it shows a starter221 connected in terminals 1 and 2 which will be connected to thefilaments of fluorescent tubes and a transformer primary 214 withsecondaries 215 connected in push-pull arrangement to transistors 216and 217. The output of the transistors is fed through the resistors 219and 220 back into the windings 221 and 222. Thus, the output ofbatteries B1 and B2 puts out a voltage which is stepped up through thewindings 215, 221, and 222 through winding 214 and into auto transformer233. This output is connected to condensers 234 and 235 to the terminals3 and 4 which will be connected to the terminals of a fluorescent lightintermittently to start it.

The foregoing specification sets forth the invention in its preferredpractical forms but the structure shown is capable of modificationwithin a range of equivalents without departing from the invention whichis to be understood is broadly novel as is commensurate with theappended claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A starting circuit for a plurality of fluorescent lamps comprising:

first switch means for connecting said plurality of lamps to a source ofpower, second switch means including an auto transformer and capacitormeans for sequentially applying a starting voltage from said source ofpower to each of said plurality of lamps, said capacitor means connectedbetween said transformer and said lamps.

1. A starting circuit for a plurality of fluorescent lamps comprising:first switch means for connecting said plurality of lamps to a source ofpower, second switch means including an auto transformer and capacitormeans for sequentially applying a starting voltage from said source ofpower to each of said plurality of lamps, said capacitor means connectedbetween said transformer and said lamps.